An obvious problem is how to protect the operator of a small boat or so-called personal water craft, when the person is alone, if the person falls overboard into the water while the boat engine is propelling the boat. The boat can continue to run on its course, leaving the operator alone in the water and in jeopardy, especially when the boat is distant from land or other boats.
A common means for protecting the operator in the prior art is as follows. A tether or lanyard runs from the operator's belt or other attachment to a plastic mechanical clip, familiarly called a “key”, which slips onto the outside of a kill switch of the boat engine. The kill switch is typically located on the control or instrument panel of the boat. It has a movable spring-loaded part which has to be held in a certain position for the boat to run. As shown in FIG. 1, such key 40 which works with the spring loaded portion of the switch is distinguished from a metal turn key 34 which turns within the switch. Hereinafter, such key 40 is referred to as a latch key. When the operator falls overboard the lanyard tensions and pulls the latch key for the switch. The spring action within the kill switch breaks the electric circuit of the engine ignition system, turning off, or “killing” the engine. Taskahsima U.S. Pat. No. 6,352,045 describes a kill switch and engine control system of such type. The presumption is that the operator can swim back to stopped boat.
The disadvantage of such prevalent type of commercial system is that use of a lanyard, although simple, inhibits the normal movement of the operator and such other persons as may be on the watercraft. Other inventors have attacked the problem of providing protection in a less inconvenient way. See for example, Simms U.S. Pat. No. 4,305,143, Boe U.S. Pat. No. 4,714,914, Morgan U.S. Pat. No. 5,021,765, Guldbrand U.S. Pat. No. 5,945,912, Murray U.S. Pat. No. 5,838,227, and Ehlers U.S. Pat. No. 7,110,694. Generally, many of the prior inventions involve having a device carried by the operator, where that device communicates with components on the boat, most often by disabling a portion of the electric system, or sending some kind of message to those who remain on the boat.
While lanyard-free systems of the type mentioned above may serve the intended purpose, they have not found wide commercial use. From inquiry and observation, the reasons appear to include: that the prior art devices lack essential simplicity and low cost of the lanyard system; that they have to be either installed at the factory, or inconveniently in the field by a skilled electrician; and, that it is difficult to adapt hard-wired systems to the diversity of boat instrument panel and wiring configurations. Thus, there is a continuing need for improvement in addressing the problem. Analogous problems are presented by land vehicles, such as motorcycles, particularly those used in racing, and by snowmobiles, where is it bad for the vehicle to keep running when the operator falls off.
Problems analogous to those presented motor boats are presented by wind or sail powered craft, in that the operator or a passenger may fall overboard. Except when the vessel is under engine power as may be sometimes the case, solutions which are useful for engine powered boats, where the ignition system is disabled, are in general not suitable. A common mode of protecting sail boat occupants with respect to falling overboard is to tether the person to a portion of the boat. But such tethers are inconvenient to use and thus they are not always used. If the person on the boat is the sole occupant and falls overboard, and the boat continues on, it is a terrible problem, especially in the open sea. So, it is a problem how to slow or stop the motion of a sail boat when a person falls overboard and the boat is sailing away. Particularly, it is a problem of how to accomplish that in a way which is economic and adaptable to the great variety of designs of sail powered craft.